Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) as a test.

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/

Do a malware check with several malware scanning programs on the Windows computer. Please scan with all programs because each program detects different malware. All these programs have free versions.

Make sure that you update each program to get the latest version of their databases before doing a scan.

• Malwarebytes' Anti-Malware:
  http://www.malwarebytes.org/mbam.php
• AdwCleaner:
  http://www.bleepingcomputer.com/download/adwcleaner/
  http://www.softpedia.com/get/Antivirus/Removal-Tools/AdwCleaner.shtml
• SuperAntispyware:
  http://www.superantispyware.com/
• Microsoft Safety Scanner:
  http://www.microsoft.com/security/scanner/en-us/default.aspx
• Windows Defender:
  http://windows.microsoft.com/en-us/windows/using-defender
• Spybot Search & Destroy:
  http://www.safer-networking.org/en/index.html
• Kasperky Free Security Scan:
  http://www.kaspersky.com/security-scan

You can also do a check for a rootkit infection with TDSSKiller.

• Anti-rootkit utility TDSSKiller:
  http://support.kaspersky.com/5350?el=88446

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked

Hi cor-el,

It took a while, but I downloaded the programs listed (where I could) and ran them. They cleared a couple of items, but did not solve the problem.

The AdwCleaner programs were both flagged by Norton as possible trojans, and would not download. The TDSSKiller did not have an XP version, nor did Windows Defender.

Has anyone heard of this specific problem before?

Hi cor-el,

Sorry, but I forgot to thank you for your fast response, and your suggestions. They're both much appreciated.

photomeister

You're welcome.

You should still give AdwCleaner a try as on Windows there is always a possibility that there is malware on the computer.

Hi cor-el,

Thanks again for your help. I turned off my virus checker (Norton), downloaded ADWCleaner, and ran it. It got rid of a few things, but I still have the same exact problem. Firefox.exe only partially starts, as before, and when I rename it to 1firefox.exe , it starts up fine.

I'm thinking of running a repair on my XP, but that's a pain. Any other ideas?

Did you boot the computer in Safe Mode?

There are some suggestions here that deal with the renamed firefox.exe program. If you haven't tried them yet then you can try them now.

• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Other_solutions

Hi cor-el,

Okay, I booted XP into safe mode, and reran the malware programs that you suggested, but there is no change.

I then repaired my XP instance using my installation CD, still no change. I deleted and re-installed Firefox under the repaired XP, and it still doesn't work.

Soooooo, I deleted Firefox 31.0, and went back to version 21.0, and it works fine. Not a great "solution", but I think I'm going to tread water until 32.0 or 33.0 are released. I'm many, many hours into this problem, and I need to take a break.

I appreciate very much your willingness to help, and I'll keep monitoring this thread and searching the `net for solid suggestions. I'm hoping to find a more direct way to follow the Firefox initiation process to see if I can pin down some specific XP or Firefox programs that I might test, investigate or replace. This is probably the toughest PC problem that I've faced so far (in about 20 years!).

Again, many thanks.